I am working in ArcGIS 10.6.
After starting the editing session I have to wait a long time before it gets activated. But then I try to select a polygon (which I have drawn before) and it won't do it. Which ever polygon I try to select; it won't select it.
I have tried to use the select tool or the Editor tool. it does not work in both examples. it highlights the polygon I want to select, but it shows in the bar below that nothing has been selected. And it also appears that nothing has been selected on my map either. I guess, that is the reason, why I cannot edit anything in my project anymore. I can daw new polygons but not edit polygons already present.

However, once I created a new polygon in the editing session it is accounted for in the menue bar below, but then I cannot cut the polygon as the cut polygon tool is still greyed out.
So: i have more or less two issues, I cannot select any previously created polygons and even if I could, I cannot modify it afterwards through cutting. And once I deselected and try to select the recently drawn polygon again it wont do it anymore.
Is there a work around to this issue, or does any bug fix exist, which I could install?